A wheel that is too small makes it hard to create nice lines (to keep arms and legs straight). A wheel that is too big, you will either not be able to spin with..

Polyurethane Protective Tape (PPT Tape) is an
Aeronautical product that is also used in the circus industry as a transparent
Grip tape to add on surfaces for adherence, on aerial rings, trapezes,
Cyr wheels and more. CircusConcepts is the only reseller of this tape in Canada outside the
aeronautical industry. 3M™ polyurethane Protective Tape is made from an
exceptionally tough abrasion resistant polyurethane Elastomer that resists
punctures, tearing, abrasion and erosion. It is formulated for resistance to
ultraviolet light. 3M 8671 Tape provides a simple, easy method of
protecting a surface from corrosion, abrasion and minor impact damage. It can
be installed in a minimum amount of time with simple tools. It can be painted
or applied over painted surfaces. 3M 8671 Tape is constructed with a
long-aging, solvent-resistant, pressure-sensitive